The present invention relates to an operating device and a system for operating a motor vehicle, which operating device and system are suitable for operating a motor vehicle with a solid-gas battery.
Motor vehicles with electric motors are an alternative to motor vehicles with conventional drive by way of internal combustion engines. An advantage of electric motors is the local absence of emissions with regard to pollutant emissions. The drive energy of an electric motor is generally provided by way of rechargeable accumulators. In this context, as accumulators, use is often made of lithium-ion batteries which impart the required drive energy for the operation of the motor vehicle.
Alternatives to lithium-ion batteries are, for example, lithium-air batteries or lithium-oxygen batteries or, more generally, solid-gas batteries, which have for example a considerably greater theoretical energy density and power capacity than present lithium-ion batteries, which can have an advantageous effect inter alia on a possible range of the motor vehicle. As a result, for motor vehicles with solid-gas batteries, special charging devices are also required, which provide the motor vehicle with the required fuel for the operation of the solid-gas battery.
The document US 2012/0041628 A1 describes a system and a method suitable for electrically charging a metal-air battery arranged in a motor vehicle. For this purpose, there are also arranged in the motor vehicle a compressor and a tank which, together with an external power source, permit a charging cycle of the metal-air battery.
An object on which the invention is based is that of providing an operating device and a system which are suitable for permitting efficient operation of a motor vehicle with solid-gas battery.
The object is achieved by way an operating element and a system in accordance with embodiments of the invention.
According to a first aspect of the invention, an operating device for operating a motor vehicle includes at least one solid-gas battery, which is designed to provide energy for an electric motor of the motor vehicle. Furthermore, the operating device includes at least one high-pressure tank for receiving and storing gas for the solid-gas battery. Furthermore, the operating device has at least one charging connection, by way of which the solid-gas battery can be coupled, during the course of a charging process, so as to receive electrical current and by way of which the high-pressure tank can be coupled, during the course of the charging process, so as to receive gas.
In this way, an operating device is realized which permits efficient operation of a motor vehicle with solid-gas battery. The solid-gas battery of the motor vehicle provides inter alia electrical energy for the drive of the motor vehicle, which electrical energy is for example converted by the electric motor of the motor vehicle into mechanical energy and thus permits propulsion of the motor vehicle. In this context, the gas that is required for the operation of the solid-gas battery is supplied to the solid-gas battery from the high-pressure tank of the motor vehicle. During the course of a charging process, it is for example possible for new gas to be supplied to the high-pressure tank of the motor vehicle by way of a charging device designed for the purpose, in order to thus permit, for example, further driving cycles.
Solid-gas batteries have an anode, which is composed of a solid, and a cathode, which is spaced apart from said anode and which is composed for example of mesoporous carbon and which may figuratively be viewed as a type of foam. Between the solid anode and the cathode, there is typically situated an electrolyte which, depending on the embodiment of the solid-gas battery, may for example be in solid or liquid form. By way of a supply of gas, a current flow is induced in the solid-gas battery, which current flow can be utilized for the purposes of supplying energy for an external electrical circuit. It is basically the case, during discharging of the solid-gas battery, that positive ions and electrodes are detached from the solid anode and pass over into the electrolyte or into the external electrical circuit. During the further process, the positive ions become coupled, at the cathode, to atoms or molecules of the supplied gas and to the electrons of the external electrical circuit, and are electrochemically bonded there. The electrons that are moved through the external electrical circuit in this process constitute the current flow, and realize an electrical supply to components coupled to the solid-gas battery. If, for example, an external voltage potential is applied to the solid-gas battery, which voltage potential exceeds the potential during the discharging of the solid-gas battery, the described process is reversed, and the solid-gas battery is charged. In this case, the electrochemical bonds between the ions of the solid anode and the atoms or molecules of the supplied gas are severed again. As a result, the ions travel through the electrolyte to the solid anode and set down on the latter by way of recombination with electrons from the external electrical circuit. Furthermore, the electrochemically bonded gas is emitted again, which gas is for example released into an exterior region of the motor vehicle or can be recirculated into the motor vehicle for a further cycle of the solid-gas battery.
In the context of the invention, the motor vehicle has at least one solid-gas battery. It is however also possible for multiple solid-gas batteries to be arranged in the motor vehicle, which solid-gas batteries are for example coupled to one another and thus realize a battery pack which provides the required drive energy for the electric motor of the motor vehicle.
In the interaction of the described operating device with a corresponding charging device, it is possible for the motor vehicle to be supplied with electrical current and/or gas for the solid-gas battery. The charging device then has, for example, a supply connection which can be coupled to the at least one charging connection of the motor vehicle and which, during the course of the charging process, permits charging with electrical current and gas.
By way of the charging device, it is the case inter alia that an electrical current is provided via the supply connection, which electrical current permits charging of the solid-gas battery. It is preferable for direct current to be provided by the charging device, because this permits a faster charging process of the motor vehicle than charging with alternating current. Charging with alternating current is however likewise possible, such that, in this context, it is for example the case that the charging device or the motor vehicle includes components for current and/or voltage conversion, such as for example a rectifier. In this way, it is ensured that the solid-gas battery of the motor vehicle is supplied with direct current which is required for the charging of the solid-gas battery. Analogously to direct current or alternating current, it is also possible by way of the charging device and the supply connection for a direct-current voltage or an alternating-current voltage to be applied, in order to thereby permit electrical charging of the solid-gas battery during the course of a charging process.
The gas that is emitted during the course of the charging process may for example be released from the solid-gas battery or from the motor vehicle, or said gas is reused for a further driving cycle of the solid-gas battery. In this case, the emitted gas is for example released from a housing of the solid-gas battery and received by the charging device, such that the charging device, during the further process, supplies the gas, for example in treated and/or compressed form, back to the high-pressure tank of the motor vehicle.
In the case of the gas being supplied in compressed form to the motor vehicle during the course of the charging process, it is possible for a greater gas volume to be stored, for example in the high-pressure tank of the motor vehicle, than would be the case with non-compressed gas. To compress the gas, it is for example the case that a compressor is integrated in the charging device, such that, during the course of the charging process, the gas can be supplied under pressure to the motor vehicle and stored in the high-pressure tank. For example, for operation of the solid-gas battery, gas is stored at a pressure of 300 bar to 700 bar in the high-pressure tank of the motor vehicle in order that, in this way, an adequate gas quantity is carried on board the motor vehicle and a desired range of the motor vehicle is thus made possible.
By virtue of the compressor being arranged externally with respect to the motor vehicle, this has an advantageous effect on the power efficiency of the solid-gas battery, because in this way, motor vehicles can be realized in which weight, volume and costs that would be involved in the case of a compressor being installed in the motor vehicle can be eliminated.
In the case of motor vehicles which do not have a dedicated compressor on board, it is for example possible, as a result of the elimination of the additional weight and volume of the compressor, to reduce the consumption of the vehicle and of the energy provided by the solid-gas battery. Furthermore, a simple and compact design is made possible, which can contribute to an inexpensive construction of the motor vehicle with solid-gas battery.
By virtue of a compressor for compressing the gas for the solid-gas battery of the motor vehicle being arranged in a charging device and not in the motor vehicle itself, a weight and volume reduction of the motor vehicle is made possible, which in turn makes it possible to realize an adaptation of further components of the motor vehicle, such as for example of the high-pressure tank. On this basis, said high-pressure tank can be made larger in terms of its dimensions than would be possible in the case of a motor vehicle with compressor. In this way, it is likewise possible, for example, for the solid-gas battery to be made larger than in the case of a motor vehicle with compressor. An enlargement of the geometrical form of the solid-gas battery and/or of the high-pressure tank increases inter alia the power capacity of the solid-gas battery and/or a gas volume that can be stored in the high-pressure tank. These geometrical adaptations can furthermore have an advantageous effect on the possible range of the motor vehicle. Consequently, the arrangement of the compressor in a charging device external to the motor vehicle contributes to more efficient operation of the solid-gas battery.
During the course of the charging process of the motor vehicle, it is also possible for emitted gas to be released from the motor vehicle via the charging connection and supplied, for example, to a charging device in order for new gas to be drawn from the charging station during the further process. A reason for this may be that a user of the motor vehicle seeks to exchange the previously used gas for a different gas type or gas mixture in order to thereby for example increase the efficiency of the solid-gas battery and the possible range of the motor vehicle. In this context, the motor vehicle and the charging device are correspondingly designed to perform such a gas exchange during the course of the charging process. Furthermore, in such a case, the solid-gas battery is designed to be operated using different gas types or gas mixtures. For example, the charging device includes a gas supply unit which has multiple gas tanks with different gas types for solid-gas batteries and provides these for the charging process of the motor vehicle. Alternatively or in addition, such a gas supply unit is also coupled to a gas supply network, and draws one or more gas types and/or gas mixtures therefrom for supply to the motor vehicle.
The charging with electrical current and gas for the solid-gas battery may for example take place simultaneously or in temporal succession during the course of the charging process by way of the charging connection of the motor vehicle. The at least one charging connection is in this case designed correspondingly for this purpose, and is coupled to the high-pressure tank and to the solid-gas battery. For example, the at least one charging connection includes an insulated electrical line for receiving and supplying the electrical current for the solid-gas battery, which insulated electrical line is surrounded by a gas line for receiving and supplying the gas for the high-pressure tank. During the course of the charging process, it is for example also possible for gas to be received from the motor vehicle via said gas line, which gas is for example emitted during the charging of the solid-gas battery. Alternatively, the operating device also includes, for this purpose, a further gas line which is for example also couplable to the charging device by way of the at least one charging connection. The at least one charging connection is, in this context, realized for example as a type of combination connection, which is thus designed so as to permit at least the described functions.
Alternatively or in addition, the described operating device has further charging connections such that, during the course of the charging process, it is for example the case that a first charging connection is available for receiving electrical current and a second charging connection is available for receiving gas for the solid-gas battery. Here, the second charging connection may also be designed for the release of gas from the motor vehicle, or it is for example the case that a gas release connection is provided which performs said function. The one or more charging connections are, in this context, designed so as to have for example common connector shapes in accordance with their function. They may however also be designed differently in terms of their shape such that, during the course of the charging process, it is at least the case that charging with electrical current and/or gas for the solid-gas battery is possible at all times.
In a refinement of the first aspect, the solid-gas battery of the motor vehicle is a metal-air battery.
The solid-gas battery or metal-air battery is for example designed to be operated with treated and/or synthetic air and/or pure oxygen, wherein, in the case of the energy being provided by way of the solid-gas battery, substantially the oxygen components of the respective gas type are electrochemically bonded during operation of the solid-gas battery. Excess nitrogen is then for example released from the motor vehicle in order to allow the oxygen to continue to pass to the reactive centers of the cathode of the solid-gas battery.
In this context, treated air refers to air without water and carbon dioxides or at least with only small fractions of water and carbon dioxides, which adversely influence the operation of the solid-gas battery even in the range from 100 to 400 ppm, and which can permanently damage the solid-gas battery. Furthermore, in the treated air, it may also be the case that further constituents have been filtered out. Synthetic air refers to a mixture of oxygen and nitrogen.
In a further refinement of the first aspect, the metal-air battery is a lithium-air battery.
In a further refinement of the first aspect, the metal-air battery is a lithium-oxygen battery.
In this context, lithium-air batteries constitute a preferred embodiment of solid-gas batteries and metal-air batteries. However, other metal-air batteries, such as for example zinc-air batteries, are also possible as a component of the operating device for the operation of the motor vehicle.
In a further refinement of the first aspect, the operating device includes an auxiliary energy store which is designed to receive and release energy.
The auxiliary energy store is for example realized as a lithium-ion accumulator, and, in combination with the solid-gas battery of the motor vehicle, constitutes a dual-store concept. The solid-gas battery represents for example a main energy store, such that the auxiliary energy store can be referred to as a secondary energy store.
For example, the auxiliary energy store is realized as one or more lithium-ion cells, or supercapacitors or hybrid capacitors are used to store additional energy and provide said energy as required. Hybrid capacitors are in this case a mixture of supercapacitors and lithium-ion cells. The auxiliary energy store may however also be assembled from multiple components which enable electrical energy to be received and output.
By comparison with the solid-gas battery of the motor vehicle, the energy content of the auxiliary energy store may be small and, for example, provide energy which corresponds to a useful power of 1-2 kWh. The stored energy from the auxiliary energy store may then for example be output in addition to the energy provided by the solid-gas battery, in order thereby to realize, for example, a performance boost of the electric motor which is required for example during an acceleration process.
In a further refinement of the first aspect, the electric motor is designed such that, during operation of the motor vehicle, during a recuperation phase, said electric motor, as a generator, converts mechanical energy into electrical energy.
In this context, the recuperation phase denotes a phase during which charging of the solid-gas battery is possible during operation of the motor vehicle. For example, received kinetic energy of the motor vehicle is, during a braking process, converted again into electrical energy, or in relation to time electrical power, by way of the electric motor by generator action, which electrical power can be supplied for example to the above-described auxiliary energy store.
Alternatively or in addition, the electrical energy thus generated is utilized for charging the solid-gas battery. Electrical charging of the solid-gas battery leads to a release of the electrochemically bonded gas, which can then in turn be utilized for example for renewed discharging of the solid-gas battery. Here, the solid-gas battery is for example surrounded by a battery housing which is designed to receive a certain gas volume in a manner dependent on a gas pressure. If the gas pressure within the battery housing exceeds, for example, a predefined threshold value, gas can be released from the battery housing for example via a pressure-limiting valve.
In a further refinement of the first aspect, the operating device includes a gas store which is designed to receive and release gas from the solid-gas battery.
Alternatively or in addition to the battery housing which can receive gas, a gas store is coupled to the solid-gas battery and receives emitted gas during the recuperation phase. For example, the gas store and/or the battery housing can receive a gas pressure of 5 bar before gas is for example released from the motor vehicle to the surroundings. During the further process, the stored gas can be supplied to the solid-gas battery again if said solid-gas battery requires gas for operational reasons. Consequently, the gas store and/or the battery housing are conducive to efficient utilization of the gas available for the operation of the solid-gas battery, without it being imperatively necessary for gas to be drawn only from the high-pressure tank of the motor vehicle.
In a further refinement of the first aspect, the operating device has a feed line which couples the high-pressure tank to the solid-gas battery. Furthermore, the operating device includes an air-conditioning system which is designed to at least partially control the temperature of the solid-gas battery and/or of the high-pressure tank and/or of the feed line.
By way of the air-conditioning system of the operating device, it is possible for the gas for the solid-gas battery to be temperature-controlled to a temperature which is advantageous for example in conjunction with the operation of the solid-gas battery and the motor vehicle. For example, by way of the air-conditioning system, a predefined temperature range of the stored gas in the high-pressure tank is maintained, which temperature range permits optimum operation of the solid-gas battery of the motor vehicle within a short time.
Gas which is drawn from a charging device during the course of the charging process can also be temperature-controlled by way of the air-conditioning system if the supplied gas has for example not already been temperature-controlled as desired by way of the charging device. The energy required for the temperature control of the gas may for example be drawn from the charging device during the course of the charging process by way of the at least one charging connection of the motor vehicle. In this way, it is for example the case that no energy is required from the solid-gas battery or from the auxiliary energy store, which is possibly conducive to a charging process coming to an end more quickly.
Depending on ambient temperatures, the gas is for example heated in the feed line before being conducted into the solid-gas battery. Alternatively, the gas in the high-pressure tank is cooled if, for example, ambient temperatures prevail which exceed an optimum operating temperature of the solid-gas battery.
Based on the Joule-Thomson effect, it is known that compressed gas cools when it expands. Consequently, it is thus possible for the compressed gas, for example from the high-pressure tank of the motor vehicle, to also contribute to cooling of the solid-gas battery. Here, the gas pressure of the stored gas must at least be higher than the gas pressure in the battery housing of the solid-gas battery in order that the gas to be supplied can propagate in the direction of the solid-gas battery.
In a further refinement of the first aspect, the operating device includes a gas release unit which is designed to release gas during operation or during the course of the charging process of the motor vehicle.
In this way, an exchange of gas for the solid-gas battery is made possible for example during the course of the charging process by way of a charging device. If the solid-gas battery is for example designed to be operated with synthetic air and pure oxygen, the gas types can be released and exchanged as required during the course of the charging process.
Furthermore, by way of the gas release unit, it is also possible during the course of the charging process for the emitted gas, which as a result of the operation during the discharging of the solid-gas battery was electrochemically bonded to the positive ions of the solid on the cathode, to be released and, for example during the course of the charging process, to be supplied to a gas-receiving unit of the charging device and to be supplied, having been compressed again, to the high-pressure tank of the motor vehicle. Here, the gas is for example conducted via pipelines from the solid-gas battery to the at least one charging connection of the motor vehicle, and during the course of the charging process, is received by a supply connection, which is coupled to the charging connection, of the charging device.
In a further refinement of the first aspect, the operating device has an electrical charging unit which is arranged in the motor vehicle and which comprises a rectifier.
During the course of a charging process, it is preferably the case that direct current or direct-current voltage is drawn by way of a charging device, whereby, in general, it is made possible to realize a charging process of the motor vehicle which comes to an end more quickly than a charging process using alternating current or alternating-current voltage. Charging using alternating current or alternating-current voltage is however likewise possible, such that the motor vehicle comprises the charging unit, which, for example by way of the rectifier, permits simple current or voltage conversion. In this way, it is ensured that the solid-gas battery of the motor vehicle is supplied with direct current or direct-current voltage is applied to the solid-gas battery, which direct current or direct-current voltage is required for the charging of the solid-gas battery.
In a further refinement of the first aspect, the operating device has a communication interface which is designed to, during the course of the charging process of the motor vehicle, exchange signals for the control of the charging process between the motor vehicle and a charging device designed for the purpose.
By way of the communication interface, it is possible for the operating device to communicate with the charging device and thus control the charging process of the motor vehicle. In this context, the charging device is, for example, equipped with a corresponding communication interface which permits such communication. For example, the communication is controlled by way of a vehicle or battery management system of the motor vehicle, which monitors inter alia the charging process. Here, the communication includes a transmission of various items of information, such as for example a status of the charging process, a system pressure, an oxygen content of the supplied gas, a fill level of the high-pressure tank, a pressure in the solid-gas battery, a gas temperature, or a battery temperature. The operating device is furthermore designed to determine the items of information and measurement values required for the communication, and can for example monitor the charging process by way of various sensors.
Owing to the communication between the operating device of the motor vehicle and the charging device, an optimum and reliable charging process for the solid-gas battery is made possible.
In a further refinement of the first aspect, the operating device has a control unit which is designed to control the operation and/or charging process of the motor vehicle.
The control unit includes for example the above-described vehicle or battery management system and, aside from the communication during the course of the charging process, also controls the discharging of the solid-gas battery and the operation of the motor vehicle.
In this context, by way of the control unit, it is for example the case that the gas pressure, an oxygen content of the gas and an exhaust-gas temperature are monitored, and for example an analysis of exhaust air, such as for example the gas released from the motor vehicle, is performed, and furthermore, a thermal management system is controlled, which thermal management system controls for example the air-conditioning system and the temperature control of the gas. For this purpose, the control unit is coupled, at least for signal transmission, to various sensors and/or the described components of the motor vehicle.
According to a second aspect, a system for operating a motor vehicle includes an operating device according to one of the above-described refinements of the first aspect and a charging device which has at least one supply connection for the supply of electrical current and/or gas for the solid-gas battery during the course of the charging process of the motor vehicle.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.